Wnt signaling agonist molecules

Abstract

Wnt signaling agonist compositions and methods for their use are provided. Wnt signaling agonists of the invention comprise a frizzled binding moiety, which is fused or conjugated to an LRP5 or LRP6 binding moiety and to an R-spondin agonist.

What is claimed is: 
     
         1 . A method of enhancing wound healing and/or tissue generation in a subject in need thereof, the method comprising providing to the subject an effective amount of a Wnt signaling agonist that dimerizes a Frizzled (Fzd) receptor with Lrp5/6, wherein the Wnt signaling agonist is covalently linked to an R-spondin agonist. 
     
     
         2 . The method of  claim 1 , wherein the R-spondin agonist is an R-spondin polypeptide or an active fragment thereof. 
     
     
         3 . The method of  claim 2 , wherein the R-spondin polypeptide is Rspo2. 
     
     
         4 . The method of  claim 2 , wherein the R-spondin polypeptide is Rspo1. 
     
     
         5 . The method of  claim 1 , wherein the R-spondin agonist is fused through a flexible linker to the Wnt signaling agonist. 
     
     
         6 . The method of  claim 1 , wherein the Wnt signaling agonist is a polypeptide comprising: a binding domain having a high affinity for one or more Fzd proteins (Fzd binding domain); and a binding domain having high affinity to one or both of Lrp5 and Lrp6 protein (Lrp5/6 binding domain). 
     
     
         7 . The method of  claim 6 , wherein the binding domains are joined through a linker. 
     
     
         8 . The method of  claim 6 , wherein the Fzd binding domain is an antibody derived binding protein, a nanobody derived binding protein, a knottin-engineered scaffold, or a norrin protein or binding fragment thereof. 
     
     
         9 . The method of  claim 6 , wherein the Fzd binding domain is an scFv comprising the six CDR regions of an anti-Fzd antibody. 
     
     
         10 . The method of  claim 6 , wherein the Lrp5/6 binding domain is an antibody derived binding protein, a nanobody derived binding domain, or a knottin-engineered scaffold. 
     
     
         11 . The method of  claim 6 , wherein the Lrp5/6 binding domain comprises an scFv comprising the six CDR regions of an anti-Lrp5 antibody or an anti-Lrp6 antibody. 
     
     
         12 . The method of  claim 6 , wherein the Lrp5/6 binding domain comprises a binding portion of a DKK protein. 
     
     
         13 . The method of  claim 1 , wherein the composition is a pharmaceutical composition comprising the Wnt signaling agonist covalently linked to the R-spondin agonist, and a pharmaceutically acceptable excipient. 
     
     
         14 . The method of  claim 7 , wherein the linker is a peptide linker comprising from 2-100 amino acids. 
     
     
         15 . The method of  claim 1 , wherein tissue generation consists of enhanced bone growth or regeneration, e.g. on bone regeneration, bone grafts, healing of bone fractures, ingrowth around prosthetic devices. 
     
     
         16 . The method of  claim 18 , wherein the contacting is performed in vivo. 
     
     
         17 . The method of  claim 18 , wherein the contacting is performed ex vivo. 
     
     
         18 . The method of  claim 17 , comprising contacting a cell population obtained from the subject with the Wnt signaling agonist covalently linked to the R-spondin agonist. 
     
     
         19 . The method of  claim 18 , wherein the cell population comprises bone marrow, bone progenitor cells, mesenchymal cells, or bone stem cells.